[ubuntu] keep dhclient running after "No DHCPOFFERS received"

http://ubuntuforums.org –
I use dhcp in /etc/network/interfaces:
auto eth0
iface eth0 inet dhcp
No network-manager installed.
This makes the dhclient run with option "-1":dhclient3 -e IF_METRIC=100 -pf /var/run/dhclient.eth0.pid -lf /var/lib/dhcp/dhclient.eth0.leases -1 eth0
dhclient manpage:
The -1 flag will cause dhclient to try once to get a lease. If it fails, dhclient exits with exit code two.When the dhcpd server is not reachable, the client exits after "No DHCPOFFERS received".
I want the dhclient keep running to get a new ip address when the dhcpd server is reachable ag
(Hardware)

I have a Lucid 64bit server implementation. I appear to have two versions of dhclient3 running at all times as shown below. I wonder whether this is normal and if not if there is a solution to fix? As can be seen both instances are attached to the same interface i.e.